Your numbers don't make sense. You should only be taxed on the gain of $275k, not the full sale price. Also define "property" in your example. Per the US Master Tax Guide (which isn't primary authority, but cites the IRC and accompanying Regs), "A capital gain or loss arises from the sale or exchange of a capital asset. Generally, the term "capital asset" means any property except the following:
1. an inventoriable asset;
4. depreciable business property;
5. real property used in the taxpayer's trade or business.
What tax rate are you using in the example?